We all long for "the old days". Heck, I remember 5¢ candy bars too. What are they now $1 or more. Inflation would only put them around 40¢
First off, the imports usually were/are not always in the greatest condition. Most guys I know bought them for a low price and then changed parts to make them the way they wanted. Adding to their initial cost.
Quality collector pieces have traditionally gone up. I collect M1Carbine. Yes, DCM sold them for $20 delivered in 1960. Using an inflation calculator the is $165 today. Forget the original cost back in the day, try and even find one for todays inflation price of $165, not a chance. They have doubled in price about every nine years. Today a nice original M1 Carbine pushes $2,000 and higher. Imports started coming in during the late 80's with stamps on the barrels at around $100 which is $206 today, and have done about the same. Today selling in the $800-$1,000.
They can be a good investment. Though I feel we mostly collect them because we just want to.